TOP SECRET The Russians have already mounted and recently intensified a cold war. There remain two other courses of action: (a) the encouragement of anti Tito elements within Yugoslavia by the infiltration of marauding bands which would be supported from across the frontier. (b) A direct Soviet military attack. 4. Our evidence leads us to believe that the present Yugoslav Government is capable of dealing with any internal threat likely to arise. A full scale Soviet invasion would however succeed, but we believe that so long as there is any possibility of overthrowing Tito by any other means the Soviet leaders will not indulge in open aggression.